Idaho’s construction industry going through agricultural waste-to-construction revolution

As CEO of Earthcraft Construction, Jon Clark represents a growing movement of Idaho builders who are transforming agricultural waste into sustainable, high-performance homes and commercial structures.

“We build the most sustainable projects in Idaho,” Clark said. “And sometimes we do that with straw bale.”

What Clark calls straw bale construction involves taking square bales of wheat straw, a byproduct of Idaho’s massive agricultural industry, and stacking them to create exterior walls that are then plastered on each side. It’s a building method that eliminates the need for manufactured insulation materials while creating structures that outperform conventional construction in nearly every metric.

The approach exemplifies Idaho’s emerging farm-to-construction pipeline, where agricultural waste becomes raw material for a green building revolution spanning from small towns like Orofino to major research facilities at the University of Idaho.

Building better with agricultural waste

Clark’s Earthcraft Construction has completed a dozen straw bale projects since building their first in Boise in 2009, which won the mayor’s Design Excellence Award the following year. The structures range from 1,100 square feet to 3,000 square feet, and all perform at notably high levels.

“I’ve got a 1,100-square-foot house that maintains temperature between 68 and 73 degrees all year round,” Clark said. “It gets well over 100 degrees in the summer here, and it gets well below freezing in the wintertime. It stays that temperature with no HVAC.”

The secret lies in eliminating thermal breaks, the continuous paths that allow heat transfer through conventional stick-frame construction. Where traditional building uses studs that create thermal bridges every 16 inches, straw bale construction creates a continuous insulative barrier with no breaks whatsoever.

Addressing thermal breaks conventionally requires expensive exterior insulation packages made from materials like extruded polystyrene, which have high embodied carbon and take significant energy to manufacture. Straw bale construction solves the problem using a waste product that requires no additional processing.

“It literally takes no added effort, no added energy, to use what is coming out of the combine or coming out of the field in order to build something with it,” Clark said. “And not only build something but build something that functions extremely well.”

Counter to intuition, straw bale structures offer exceptional fire resistance. Clark points to real-world evidence from California wildfires, where straw bale buildings survived with only minor exterior discoloration while conventional structures burned.

The fire resistance comes from the bales’ extreme density, which prevents the oxygen flow necessary for combustion. ASTM testing, the standardized laboratory testing in the United States, subjected straw bale walls to flame jets for two hours. The walls passed with what Clark calls “flying colors,” with test proctors saying they felt the walls could have withstood much longer exposure.

“The bail wall doesn’t allow [combustion]. You need heat and oxygen to combust, and the bail wall doesn’t allow that,” Clark said.

Straw bale construction also offers superior sound attenuation, seismic performance and moisture regulation. The walls passively breathe, preventing the buildup of carcinogens that can accumulate in tightly sealed conventional homes.

What’s more, straw bale is easier to get. It’s cheaper too.

Local sourcing and economic benefits

Clark sources his straw bales from farms within 30 miles of the Treasure Valley, working with producers who bale tightly and avoid pesticides. Idaho cultivates wheat in 48 of its 50 counties, making straw bales readily available statewide.

“Whether you’re building a 1,100-square-foot small house, or whether you’re building a 3,000-square-foot house, or whether you’re building a 10,000-, 20,000-square-foot commercial structure, you are going to be getting a vast majority of your materials from within 100 miles,” Clark said.

This local sourcing contrasts sharply with conventional construction materials, which travel through complex supply chains. Clark noted that engineered wood products rely on resin from just two massive plants in the United States, creating transportation-intensive spider webs of material movement.

“I’m keeping my money locally with [straw bales], but I’m also keeping my money locally by sourcing my posts and my beams from local mills,” Clark said. The approach reduces transportation carbon by 60% while supporting local agriculture and timber industries.

Clark’s work represents part of a statewide transformation. In Orofino, Susan Jacobson, director of Clearwater County Economic Development, describes emerging biotech companies converting forest and agricultural waste into various products, including building materials.

“There’s a lot going on now in the biotech economy, so many different products being made from forest and ag waste,” Jacobson said. “Instead of burning slash piles, now they’re turning it into usable products.”

Companies like Hempitecture have opened large-scale manufacturing facilities in Jerome, processing 36,000 pounds of industrial hemp every two weeks into HempWool thermal insulation.

Hemp sequesters approximately nine tons of CO2 per acre during its growing season while requiring no pesticides or fertilizers.

“Where you use conventional insulation, you can use hemp wool,” Hempitecture founder Matthew Mead told Idaho Farm Bureau Federation. “Our goal is to produce more sustainable and high-performing bio-based building materials.”

University research leadership

Private companies aren’t the only ones eyeballing the farm-to-construction pipeline. The University of Idaho has also emerged as a leader in sustainable construction research. The $51 million ICCU Arena showcases mass timber construction using wood harvested from the university’s Experimental Forest and processed by Idaho mills into glue-laminated beams.

Since 1986, the university has used biomass from local forest industries to power its District Energy Plant. In 2022, the university installed electricity-producing steam turbines that offset 13% of campus electrical demand, making the facility the first carbon-negative building on campus.

The university’s Forest and Sustainable Products program examines natural fiber and wood composites while researching lignocellulosic biomass chemistry for developing sustainable materials from waste streams.

Idaho National Laboratory too operates the Biomass Feedstock National User Facility, offering technology and expertise to help the bioenergy industry overcome biomass processing challenges. Research shows 51% of agricultural waste biomass studies focus on developing binding agents, aggregates and additives for soil, cement and concrete applications.

Despite technological advances, Clark identifies education as the primary barrier to scaling sustainable construction. He advocates for local incentives including property tax reductions and permit fee breaks for green building projects. Clark suggests municipalities could recover such incentive costs through increased local economic activity from sourcing materials regionally rather than through national supply chains.

Some are already on board. The City of Boise has implemented a Green Building Code offering dedicated project management for sustainable construction, while Idaho offers income tax deductions for energy efficiency upgrades in pre-2002 homes. Idaho Power provides cash incentives for energy-efficient new construction, offering up to 20 cents per kilowatt hour saved for custom projects.

Overcoming market resistance

Clark acknowledges that sustainable construction requires builders willing to work outside conventional practices.

“You kind of got to have balls to do it, and you got to be a little bit OK with some risk,” Clark said. “It takes a little bit of education, takes a little bit outside the box thinking.”

Cost isn’t the barrier. Clark’s straw bale homes cost the same as conventional construction while offering superior performance. The challenge lies in market education and builder willingness to adopt different methods.

“People don’t know about it, and you don’t have builders who are willing to take the risks like me,” Clark said. “Building conventionally is thought of as safer because everybody’s doing it.”

To address education gaps, Clark hosts “Learn and Burn” events where he sets different wall assemblies on fire to demonstrate straw bale performance. His July event at the Wildland Fire Foundation facility near Boise airport drew fire marshals, city officials, architects and families, and it’s part of his plan to shed light on how effective green construction can be.

Economic and environmental impact

Construction and demolition waste accounts for 30-40% of the total solid waste stream globally, with Idaho facilities like Western Recycling diverting more than 5 billion pounds of material from landfills since 1979.

Idaho’s forest industry harvested more than 1 billion feet of timber in 2021, generating $2.5 billion in lumber-related products and supporting more than 30,500 jobs statewide. Expanding sustainable construction could create additional value streams for agricultural and forestry operations.

“The difference between what I do [from manufacturers] is that I don’t have to manufacture anything,” Clark said. “I’m taking literally the straight byproduct of the cultivation of wheat, and I don’t have to do anything special to it.”

Tom Kealey, Idaho Department of Commerce director, told Idaho Farm Bureau Federation that the state’s agricultural industry attracts companies seeking sustainable material sources.

“Our state’s rich agriculture industry is one of the reasons companies chose to locate in our state,” Kealey said.

The convergence of agricultural waste streams, university research, emerging technologies and supportive policies positions Idaho at the forefront of sustainable construction. From Clark’s Treasure Valley projects to Orofino’s biotech facilities to University of Idaho research labs, the state is proving that agricultural waste represents raw material for a construction revolution benefiting farmers, builders and the environment.

“There are straw bale houses that are well over 100 years old that are still standing and being occupied and healthy, and they are not showing any signs of deterioration,” Clark said. “This is not a new thing. It’s been around for well over 150 years.”

As Idaho builders like Clark demonstrate the viability of agricultural waste construction materials, the challenge shifts from proving performance to scaling adoption through education and supportive policies that recognize the economic and environmental benefits of keeping building materials local.